Fig. 2

Suppressive effects of ARE (a) and ARE-F (b) on the proMMP-9 elevation in HaCaT keratinocytes under UV-B irradiation. HaCaT cells were subjected to the varying concentrations (0, 2, 20 and 80 μg/mL) of ARE (a) and ARE-F (b) for 1 h before the irradiation. The proMMP-9 proteins in cellular lysates, detected using western blotting analysis, were expressed as a percentage (%) of the corresponding non-irradiated control. In the lower panels of both a and b, the band strength was determined with densitometry using the ImageJ software which can be downloaded from the NIH website. #P < 0.05; ###P < 0.001 versus the non-irradiated control. *P < 0.05; **P < 0.01; ***P < 0.001 versus the non-treated control (UV-B irradiation alone)